Cooling system questions
 

I take out my radiator to clean outside and inside, impressive all the mud between the fins and hair, grass. but the ac condensator (ac radiator ) was worst.

I had or have (hope not) mixing problems, I believe was the oil cooler, I already fix it, I recently change my head gasket but the head was not the problem.

Before I add to the engine the mobil 1 and the watercooler I will use normal new cheap engine oil and water to check if my mixing problem are completely resolved or not.

Then I clean my radiator and I will change all the water hoses that I alredy have it.

But I found that my radiator was rapaired 3 times and I found that have a lot of oxide (rust )inside.

I try to clean it with soap and I already clean the oil but the rust still in the radiator, then in this moment is soak in fuel (gasoline) to try to remove the oxide, later I will clean again with soap.

questions

1.- If the radiator and the engine are made of aluminum why exist a lot of rust ?

2.- I know that my car had 19 years old but do this radiator have a lot of problems ?

3.- Do you know a better way to clean the radiator ?

let me know
regards

Why not just buy a new one? They're not too expensive, and with three repairs it's bound to leak again, you can count on it.

Rust would indicate that the wrong coolant is being used [containing phosphate]...have you used de-ionized water? Seems like that might also bond to your engine and cause corrosion.